Seattle City Attorney Pete Holmes, left, looks on as Mayor Jenny Durkan speaks at a news conference announcing plans for the city to move to vacate misdemeanor marijuana possession convictions, Thursday, Feb. 8, 2018, in Seattle. City Council member Bruce Harrell looks on at right. Five years after Washington state legalized marijuana, Seattle officials say they're moving to automatically clear past misdemeanor convictions for pot possession. San Francisco recently took the same step. (AP Photo/Elaine Thompson)

SEATTLE - More than five years after Washington state legalized marijuana, Seattle officials said Thursday they're moving to automatically clear past misdemeanor convictions for pot possession a step similarly announced by San Francisco last week.

During a press conference on Thursday, Seattle Mayor Jenny Durkan said the misdemeanor marijuana convictions were a barrier to housing, jobs and education.

"It is a necessary step to right the wrongs of what was a failed war on drugs," Durkan said.

The mayor emphasized the effect that a conviction has on a person's life. "It really forecloses opportunities...," she said.

Durkan also stated that the war on drugs had implicit racial bias, saying a person was three times as likely to be convicted of a marijuana crime if they were a person of color.

"We as a society made a mistake," she said during the press conference. "We can't give you back all those years but what we can say is we can erase the criminal conviction."

The city doesn't actually have that many convictions to clear: between 500 and 600 over the span of about 13 years, City Attorney Pete Holmes said. They date from about 1997, when the Legislature dictated that municipal courts, rather than county district courts, would handle those misdemeanors, and 2010 when Holmes became city attorney and stopped prosecuting low-level pot cases entirely.

"I have never filed one except, as we understood it, one slipped by in that first few days in office, where a plea was entered," Holmes said during the press conference. "I'm anxious to find that particular one to make sure it's teed up, right up front."

John Novak, editor of the website 420Leaks that has been critical of the state’s handling of medical marijuana, calls the decision, "a step in the right direction."

After authorities raided his marijuana grow operation, he was charged with felony and several misdemeanors that were eventually dismissed.

He said he knows the long-term impacts a charge can have on someone’s life.

“I had a small garden nursery and the day after I was raided my customers were gone,” said Novak. “It definitely has an effect on your life."

The city plans to file a single motion next week in municipal court to clear the convictions and will set up a website where people can check their cases, Durkan said.

"We believe justice should not wait...we are going to act where we can act and we hope it is an example for others," Durkan said.

Marijuana possession arrests in Washington state rose sharply in the 25-year period from 4,000 in 1986 to 11,000 in 2010, totaling 240,000 arrests, according to the Drug Policy Alliance.

During that period, African-Americans were arrested at nearly three times the rate of whites. Latinos and Native Americans were arrested at 1.6 times the rate of whites.

Seattle's decision to vacate past pot convictions follows a similar move by the city of San Francisco.

San Francisco District Attorney George Gascón said last week that his office will dismiss and seal 3,038 misdemeanor convictions dating back before California's legalization of marijuana went into effect, with no action necessary from those who were convicted.

Prosecutors will also review up to 4,940 felony convictions and consider reducing them to misdemeanors.